JPS595111Y2 - 2-stage enlargement bit - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a two-stage enlarged bit that is attached to the tip of a spiral auger in the medium excavation method of light soil consolidation.

The purpose of this is to provide something with a simple structure and reliable operation, and in this invention, an external A cylinder is provided so as to be rotatable relative to the main shaft at a predetermined angle, and an enlarged end having a protrusion at the end of the plate on the circumference of the outer cylinder is provided on the main shaft of an appropriate number of tools so as to be freely rotatable radially about the axis of the main shaft. An appropriate number of stoppers that can be supported and engaged with the protrusion at two places, such as the inclined bottom surface and the inner surface, are fixed to the guide vane fixed to the main shaft, and the enlarger is maintained in a closed state by its own weight during normal times. When the spindle rotates forward, the protrusion comes into contact with a part of the stopper to maintain a one-step enlarged state, and after the spindle is reversed by a predetermined angle, it rotates forward again, so that the protrusion engages with the other part of the stopper. Maintaining the two-stage expanded state, inserting the concrete pile into the hollow part in the closed state, excavating a sinking hole with a diameter approximately equal to the outer diameter of the concrete pile in the first-stage expanded state, and solidifying the tip of the bulb in the second-stage expanded state. Excavation of an enlarged hole for construction.

That is, the feature of the present invention is that mechanical two-step enlargement operation is performed by the interaction between a protrusion provided integrally with the enlarging tool and a stopper provided that can be engaged with the protrusion in two ways. This is possible by making the enlarged bit simple in structure, easy to manufacture, and reliable in operation.

An example of implementing the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the main parts of the enlarged bit of the present invention.
A stopper 11 is fixed to the guide vane 12 and comes into contact with a protrusion 10 integrally provided on the enlarging tool 8, thereby showing the enlarged state of the enlarging tool 8.

An actuating member 18 is provided fixed to the main shaft 6, while a first engaging member 16 and a second retaining member 17 are provided on the outer cylinder 7 which is rotatably inserted relative to the main shaft 6. is fixed in place.

By rotating the main shaft 6 in the forward and reverse directions, the actuating member 18 is engaged with the first engaging member 16 and the second engaging member, respectively, and the expanding tool 8 is expanded.

Figures 2 and 3 are longitudinal cross-sectional views and plan views in each operating state. In the figures, 1 is a concrete pile, 2 is a hollow part of the pile 1, 3 is a spiral auger shaft, and 4 is a concrete pile where the pile 1 is sunk. 5 is a two-stage expansion bit of the present invention, and 6 is its main shaft, which can be freely connected to the tip of the spiral auger shaft 3.

Note that the main shaft 6 may be directly constructed as an extension of the spiral auger shaft 3.

7 is an outer cylinder fitted to be rotatable relative to the main shaft 6 at a predetermined angle, and 8 is an enlarger, one end of which is attached to a suitable number of rotatably around the circumference of the outer cylinder 7 via a shaft 9 (Fig. In the example of 2), it is pivoted,
It can be opened and closed radially with respect to the axis of the main shaft 6.

Reference numeral 10 denotes a protrusion fixedly protruding from the plate end of the enlarging tool 8, and 11 a stopper, which protrudes downward and is fixed to a guide vane 12 provided integrally with the main shaft 6.

Reference numeral 13 denotes a nozzle hole J4 drilled in the center of the main shaft 6 for spouting air and/or cement milk. The nozzle hole J4 is a valve provided at the tip of the nozzle hole 13, which is made of an elastic material such as rubber and opens and closes the tip of the nozzle hole. do.

15 is a tip digging blade.

The operation of the enlargement bit of the present invention having the above configuration will be explained.

When connecting the two-stage enlarged bit 5 to the tip of the spiral auger shaft 3 and inserting it into the hollow part 2 of the concrete pile 1,
As shown in FIG. 2A, since the enlarging tool 8 hangs down due to its own weight, its insertion is not obstructed.

When the concrete pile 1 is erected and the expanding bit 5 is inserted into the hollow part 2, and the expanding tool 8 contacts the ground, the spiral auger 3 is further lowered, and as shown in FIG. Further, as shown in FIG. 3A, the free end of the enlarging tool 8 receives the earth pressure and rotates until the protrusion 10 abuts against the stopper 11 and expands, resulting in a further enlarged state.

When the spiral auger 3 is rotated in the normal direction (clockwise) in this one-stage expanded state, the operating member 18 rotates the expanding bit 5 while maintaining the engaged state with the first engaging member 16, and the outer diameter of the concrete pile 1 is approximately equal to the diameter of the concrete pile 1. A sink hole 4 of equal diameter is excavated.

At this time, air or the like is supplied through the ejection hole 13 as necessary to promote the discharge action of the excavated earth and sand of the spiral auger by the above-mentioned excavation and air lift.

The concrete pile 1 is deposited a predetermined distance, and the main shaft 6 is moved by the spiral auger shaft 3 as shown by the arrow in FIG. 3A.
When the is reversed (counterclockwise), the enlarging tool 8 is in contact with the excavated hole, so it receives the resistance and remains stationary without being reversed together with the outer cylinder 7. On the other hand, the stopper 11 is reversed together with the main shaft 6 and remains stationary. With the positional relationship shown in Figure 2B, the main shaft 6
When it is lowered, the protrusion 10 is at a position deviated from the stopper 11 by a predetermined angle, so that the enlarging tool 8 further rotates upward and expands.

Next, when the main shaft 6 is rotated in the forward direction as shown by the arrow in FIG. Maintain the stage enlarged state (see Figures 2B and 3C).

In this two-stage enlarged state, rotate the screw auger shaft 3 in the normal direction,
A hole 4' for the tip of the root hardening bulb, which has a diameter larger than the outer diameter of the concrete pile 1, is excavated.

At this time, cement milk is supplied from the ejection hole 13, and the excavated earth and sand and cement milk are stirred by the expanding tool 8 to form one tip-hardened bulb.

Finally, when pulling out the enlarged bit 5 from the hollow part 2 of the concrete pile 1, the spiral auger shaft 3 is reversed once and the relative relationship between the stopper 11 and the protrusion 10 is adjusted as shown in FIG. 3B.
state, and after releasing the engagement between the protrusion 10 and the collar 11, pull it out. is possible.

As explained above, the enlarging bit of the present invention has an outer cylinder with an enlarging tool pivotally supported on the main shaft, which is rotatable relative to a predetermined angle, and a stopper fixed to the guide vane of the main shaft, and a protrusion integrally formed with the enlarging tool. Since it has a mechanically lockable structure, it has a simpler structure and is advantageous in manufacturing, and is easier to maintain and inspect than, for example, an expanding bit that maintains a two-stage expanded state using hydraulic pressure.

In addition, the operation is extremely simple, as the main shaft can be shifted to the enlarged state simply by rotating the main shaft in reverse and forward directions via the screw auger shaft.

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention, and FIG. 1 is a perspective view, and FIGS. 2A, B, and 3A, B, and C are longitudinal sectional views and plan views in each operating state. . In the above figure, each symbol indicates the following. 1: Concrete pile, 2: Hollow part, 3: Spiral auger shaft, 4: Submersion hole, 4': Foot protection bulb creation hole, 5:
2-stage enlargement bit, 6: main shaft, 7: outer cylinder, 8: enlarger, 9
: shaft, 10: protrusion, 11: stopper, 12: guide vane,
13: Spout hole, 14: Valve, 15: Tip excavating blade, 16: First engaging member, 17: Second retaining member, 18: Operating member.

Claims (1)

[Scope of utility model registration request] A main shaft 6 connected to the tip of a spiral auger shaft 3 used in the medium excavation method is provided with an outer cylinder 7 so as to be relatively rotatable at a predetermined angle, and a projection 10 is provided at the plate end on the circumference of the outer cylinder 7. One end of the tool 8 is supported by an appropriate number of shafts so as to be rotatable radially around the axis of the main shaft 6, and a projection 1 corresponding to each of the projections 10 is provided.
This is a two-stage enlarged bit in which a stopper 11 that can be secured at two places, such as the inclined bottom surface and the inner surface, is integrally formed with the main shaft 6.